ho risolto così
codice:if (objCode<% = strNomeInput %>.value!='') { top.nomeiframe<% = strNomeInput %>.location='RelatedTopicUtility.asp?InputType=Code&InputTypeParameter=' + strCode + '&InputName=7&onlyReleasedTopics=5&IdExcludedTopic=3'; objCode.value=''; };